1. Field of the Invention
The invention relates generally to a heater block installed within a chamber in chemical vapor deposition (CVD) apparatus used to manufacture a semiconductor device. More particularly, the present invention relates to a heater block having a catalyst spray means.
2. Description of the Prior Art
Generally, a metal wiring in a semiconductor device is formed of aluminum (Al), tungsten (W), titanium (Ti), etc. These metals are deposited by means of physical vapor deposition (PVD) or chemical vapor deposition (CVD) methods. Of them, the CVD method is a method by which a metal precursor in a gaseous state is sprayed onto the surface of a wafer, so that the metal is deposited on a wafer due to chemical reaction of the precursor. These processes are performed within the chamber in the CVD apparatus.
Within the chamber of the CVD apparatus is installed a showerhead for uniformly spraying the precursor in a gaseous state supplied from a precursor delivery apparatus onto the surface of the wafer. At the bottom of the showerhead, that is, at the bottom of the chamber is installed a heater block for maintaining the wafer at an adequate temperature during the deposition process.
With the integration level and speed of semiconductor devices becoming higher, however, there is a limitation in the coverage and the burial characteristics of metal. Therefore, as time goes on, it is difficult to use the above-mentioned metals, therefore copper (Cu) is increasingly used as a new metal wiring material.
However, if Cu is deposited using CVD apparatus, as constructed above, the adhesive force and the quality of the film become degraded, lowering the electrical characteristic of devices and severely lowering the deposition speed, thus lowering the yield of devices.
In order to increase the deposition speed while improving the film quality of Cu, it is useful that a catalyst made of a chemical additive (enhancer) be uniformly sprayed on the surface of the wafer. In a conventional chamber, however, there is not an apparatus for spraying catalyst. Therefore, it is difficult to increase the deposition speed and improve the film quality of Cu.